1. Field of the Invention
The present invention relates to novel active compound combinations comprising firstly at least one known compound from the class of the tetronic or tetramic acids and secondly at least one further known active compound of the formula (I), which combinations are highly suitable for controlling animal pests, such as insects and unwanted acarids.
2. Description of Related Art
It is already known that compounds of the formula (I)
in which    R represents methyl or cyclopropyl    have insecticidal activity (cf. EP-A 0 539 588). Specifically, these are the compound of the formula (Ia)
and the compound of the formula (Ib)

Furthermore, it is known that compounds of the formula (II)
in which either    R1=CH3     R2=H    R3=CH3     R4=H    R5=OC2H5     R6=OCH3     n=1    X=N—Hor    R1=Cl    R2=Cl    R3=H    R4=H    R5=C(CH3)2C2H5     R6=H    n=1    X=Oor    R1=CH3     R2=CH3     R3=H    R4=CH3     R5=CH2—C(CH3)3     R6=H    n=O    X=Ohave insecticidal properties (cf. EP-A-528 156 and EP-915 846).
Accordingly, formula (II) comprises the following compounds of the formulae (IIa), (IIb) and (IIc) having the common names spirotetramate (IIa), spirodiclofen (IIb) and spiromesifen (IIc), the compound of the formula (IIa) being present in the cis-configuration (cf. EP-A-01523472) or as a mixture of the cis and trans configuration:
